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Sulfenic Acid
In chemistry, a sulfenic acid is an organosulfur compound and oxoacid with the general formula . It is the first member of the family of organosulfur oxoacids, which also include sulfinic acids () and sulfonic acids (), respectively. The base member of the sulfenic acid series with R = H is hydrogen thioperoxide. Properties In contrast to sulfinic and sulfonic acids, simple sulfenic acids, such as methanesulfenic acid, CH3SOH, are highly reactive and cannot be isolated in solution. In the gas phase the lifetime of methanesulfenic acid is about one minute. The gas phase structure of methanesulfenic acid was found by microwave spectroscopy (rotational spectroscopy) to be CH3–S–O–H. Sulfenic acids can be stabilized through steric effects, which prevent the sulfenic acid from condensing with itself to form thiosulfinates, RS(O)SR, such as allicin from garlic. Through the use of X-ray crystallography, the structure of such stabilized sulfenic acids were shown to be R–S–O–H. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxiredoxins
Peroxiredoxins (Prxs, ; HGNC root symbol ''PRDX'') are a ubiquitous family of antioxidant enzymes that also control cytokine-induced peroxide levels and thereby mediate signal transduction in mammalian cells. The family members in humans are PRDX1, PRDX2, PRDX3, PRDX4, PRDX5, and PRDX6. The physiological importance of peroxiredoxins is indicated by their relative abundance (one of the most abundant proteins in erythrocytes after hemoglobin is peroxiredoxin 2). Their function is the reduction of peroxides, specifically hydrogen peroxide, alkyl hydroperoxides, and peroxynitrite. Classification Prxs were historically divided into three (mechanistic) classes: typical 2-Cys Prxs, atypical 2-Cys Prxs, and 1-Cys Prxs. The designation of "1-Cys" and "2-Cys" Prxs was introduced in 1994 as it was noticed that, among the 22 Prx sequences known at the time, only one Cys residue was absolutely conserved; this is the residue now recognized as the (required) peroxidatic cysteine, CP ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine
Cysteine (; symbol Cys or C) is a semiessential proteinogenic amino acid with the chemical formula, formula . The thiol side chain in cysteine enables the formation of Disulfide, disulfide bonds, and often participates in enzymatic reactions as a nucleophile. Cysteine is chiral, but both D and L-cysteine are found in nature. LCysteine is a protein monomer in all biota, and D-cysteine acts as a signaling molecule in mammalian nervous systems. Cysteine is named after its discovery in urine, which comes from the urinary bladder or cyst, from Ancient Greek, Greek κύστις ''kýstis'', "bladder". The thiol is susceptible to oxidation to give the disulfide bond, disulfide derivative cystine, which serves an important structural role in many proteins. In this case, the symbol Cyx is sometimes used. The deprotonated form can generally be described by the symbol Cym as well. When used as a food additive, cysteine has the E number E920. Cysteine is Genetic code, encoded by the codo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prasugrel
Prasugrel, sold under the brand names Effient and Efient, is a medication used to prevent formation of blood clots. It is a platelet inhibitor and an irreversible antagonist of P2Y12 ADP receptors and is of the thienopyridine drug class. It was developed by Daiichi Sankyo Co. and produced by Ube and marketed in the United States in cooperation with Eli Lilly and Company. Prasugrel was approved for use in the European Union in February 2009, and in the US in July 2009, for the reduction of thrombotic cardiovascular events (including stent thrombosis) in people with acute coronary syndrome (ACS) who are to be managed with percutaneous coronary intervention (PCI). Medical uses Prasugrel is used in combination with low-dose aspirin to prevent thrombosis in patients with acute coronary syndrome, including unstable angina pectoris, non- ST elevation myocardial infarction ( NSTEMI), and ST elevation myocardial infarction ( STEMI), who are planned for treatment with PCI. Pras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clopidogrel
Clopidogrel, sold under the brand name Plavix among others, is an antiplatelet drug, antiplatelet medication used to reduce the risk of Cardiovascular disease, heart disease and stroke in those at high risk. It is also used together with aspirin in myocardial infarction, heart attacks and following the placement of a Coronary stent, coronary artery stent (management of acute coronary syndrome#Antiplatelet drugs, dual antiplatelet therapy). It is taken Oral administration, by mouth. Its effect starts about two hours after intake and lasts for five days. Common side effects include headache, nausea, easy bruising, itching, and heartburn. More severe side effects include bleeding and thrombotic thrombocytopenic purpura. While there is no evidence of harm from use during pregnancy, such use has not been well studied. Clopidogrel is in the thienopyridine-class of antiplatelets. It works by irreversibly inhibiting a receptor called P2Y12, P2Y12 on platelets. Clopidogrel was paten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ticlopidine
Ticlopidine, sold under the brand name Ticlid, is a medication used to reduce the risk of thrombotic strokes. It is an antiplatelet drug in the thienopyridine family which is an adenosine diphosphate (ADP) receptor inhibitor. Research initially showed that it was useful for preventing strokes and coronary stent occlusions. However, because of its rare but serious side effects of neutropenia and thrombotic microangiopathy it was primarily used in patients in whom aspirin was not tolerated, or in whom dual antiplatelet therapy was desirable. With the advent of newer and safer antiplatelet drugs such as clopidogrel and ticagrelor, its use remained limited. It was patented in 1973 and approved for medical use in 1978. Medical uses Ticlopidine is indicated for the prevention of strokes and when combined with aspirin, for people with a new coronary stent to prevent closure. Stroke Ticlopidine is considered a second-line option for the prevention of thrombotic strokes among p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esomeprazole
Esomeprazole, sold under the brand name Nexium r Neksiumamong others, is a medication which reduces stomach acid. It is used to treat gastroesophageal reflux disease, peptic ulcer disease, and Zollinger–Ellison syndrome. Its effectiveness is similar to that of other proton pump inhibitors (PPIs). It is taken by mouth or injection into a vein. Common side effects include headache, constipation, dry mouth, and abdominal pain. Serious side effects may include angioedema, Clostridioides difficile infection, and pneumonia. Use in pregnancy appears to be safe, while safety during breastfeeding is unclear. Esomeprazole is the (''S'')-(−)-enantiomer (or less specifically the S-isomer) of omeprazole. It works by blocking H+/K+-ATPase in the parietal cells of the stomach. It was patented in 1993 and approved for medical use in 2000. It is available as a generic medication and sold over the counter in several countries. In 2022, it was the 122nd most commonly prescribed medic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omeprazole
Omeprazole, sold under the brand names Prilosec and Losec, among others, is a medication used in the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger–Ellison syndrome. It is also used to prevent upper gastrointestinal bleeding in people who are at high risk. Omeprazole is a proton-pump inhibitor (PPI) and its effectiveness is similar to that of other PPIs. It can be taken by mouth or by injection into a vein. It is also available in the fixed-dose combination medication omeprazole/sodium bicarbonate as Zegerid and as Konvomep. Common side effects include nausea, vomiting, headaches, abdominal pain, and increased intestinal gas. Serious side effects may include ''Clostridioides difficile'' colitis, an increased risk of pneumonia, an increased risk of bone fractures, and the potential of masking stomach cancer. Whether it is safe for use in pregnancy is unclear. It works by blocking the release of stomach acid. Omeprazole was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DART Ion Source
In mass spectrometry, direct analysis in real time (DART) is an ion source that produces electronically or vibronically excited-state species from gases such as helium, argon, or nitrogen that ionize atmospheric molecules or dopant molecules. The ions generated from atmospheric or dopant molecules undergo ion-molecule reactions with the sample molecules to produce analyte ions. Analytes with low ionization energy may be ionized directly. The DART ionization process can produce positive or negative ions depending on the potential applied to the exit electrode. This ionization can occur for species desorbed directly from surfaces such as bank notes, tablets, bodily fluids (blood, saliva and urine), polymers, glass, plant leaves, fruits & vegetables, clothing, and living organisms. DART is applied for rapid analysis of a wide variety of samples at atmospheric pressure and in the open laboratory environment. It does not need a specific sample preparation, so it can be used for the ana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syn-propanethial-S-oxide
''syn''-Propanethial ''S''-oxide (or (''Z'')-propanethial ''S''-oxide), a member of a class of organosulfur compounds known as thiocarbonyl S-oxide, ''S''-oxides (formerly "sulfines"), is a volatile liquid that acts as a lachrymatory agent (triggers tearing and stinging on contact with the eyes). Onion release The chemical is released from onions, ''Allium cepa'', as they are sliced. The release is due to the breaking open of the onion cells, which releases enzymes called alliinases. Alliinases then break down amino acid sulfoxides, generating sulfenic acids. A specific sulfenic acid, allicin or 1-propenesulfenic acid, is rapidly rearranged by another enzyme, the lachrymatory factor synthase (LFS) to give ''syn''-propanethial ''S''-oxide. Vapors from this volatile liquid induces tearing. Related compounds A structurally related lachrymatory compound, ''syn''-butanethial ''S''-oxide, C4H8OS, has been found in another genus ''Allium'' plant, ''Allium siculum''. Propanethial S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allium
''Allium'' is a large genus of monocotyledonous flowering plants with around 1000 accepted species, making ''Allium'' the largest genus in the family Amaryllidaceae and among the largest plant genera in the world. Many of the species are edible, and some have a long history of cultivation and human consumption as a vegetable including the onion, garlic, scallion, scallions, shallot, shallots, leek, leeks, and chives, with onions being the second most grown vegetable globally after tomatoes as of 2023. ''Allium'' species occur in temperate climates of the Northern Hemisphere, except for a few species occurring in Chile (such as ''A. juncifolium''), Brazil (''A. sellovianum''), and tropical Africa (Allium spathaceum, ''A. spathaceum''). They vary in height between . The flowers form an umbel at the top of a leafless stalk. The bulbs vary in size between species, from small (around 2–3 mm in diameter) to rather large (8–10 cm). Some species (such as Wels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
